1 files changed, 52 insertions, 32 deletions

diff --git a/ByteBuffer.cpp b/ByteBuffer.cpp
index f27deeb..c5f7905 100644
--- a/ByteBuffer.cpp
+++ b/ByteBuffer.cpp
@@ -1,5 +1,4 @@
 #include "ByteBuffer.h"
-#include <stdint-gcc.h>
 #include <string.h>
 #include <sstream>
 #include <iomanip>
@@ -7,75 +6,96 @@
 
 using namespace std;
 
-ByteBuffer::ByteBuffer(uint8_t *bytes, size_t capacity, size_t size, size_t zero) :
-        bytes(bytes), capacity(capacity), size(size), cursor(zero), zero(zero) {
+ByteBuffer::ByteBuffer(uint8_t *bytes, size_t capacity) :
+        bytes(bytes), capacity(capacity), zero(&bytes[0]), end(&bytes[capacity]) {
+    ptr = &bytes[0];
+}
+
+ByteBuffer::ByteBuffer(uint8_t *bytes, size_t capacity, size_t zero, size_t size) :
+        bytes(bytes), capacity(capacity), zero(&bytes[0]), end(&bytes[size]) {
     assert(zero <= size);
+    assert(size <= capacity);
+    ptr = &bytes[0];
+}
+
+ByteBuffer::ByteBuffer(const uint8_t *bytes, size_t capacity, uint8_t *zero, uint8_t *end) :
+        bytes(bytes), capacity(capacity), zero(zero), end(end), ptr(zero) {
 }
 
 ByteBuffer &ByteBuffer::add8(uint8_t value) {
-    checkAndUpdateSize(1);
-    bytes[zero + cursor++] = value;
+    checkAndUpdateEnd(1);
+    (*ptr++) = value;
     return *this;
 }
 
 ByteBuffer &ByteBuffer::add16le(uint16_t value) {
-    checkAndUpdateSize(2);
-    bytes[zero + cursor++] = (uint8_t) (value & 0xff);
-    bytes[zero + cursor++] = (uint8_t) ((value >> 8) & 0xff);
+    checkAndUpdateEnd(2);
+    (*ptr++) = (uint8_t) (value & 0xff);
+    (*ptr++) = (uint8_t) ((value >> 8) & 0xff);
     return *this;
 }
 
 uint8_t ByteBuffer::get8(size_t index) {
-    canAccessIndex(index);
-    return bytes[zero + cursor];
+    assertCanAccessRelative(index);
+    return *ptr++;
 }
 
 uint8_t ByteBuffer::get8() {
-    canAccessIndex(cursor);
-    return bytes[zero + cursor++];
+    assertCanAccessRelative(1);
+    return *ptr++;
 }
 
 uint16_t ByteBuffer::get16le() {
-    canAccessIndex(cursor + 1);
+    assertCanAccessRelative(1);
     uint16_t value;
-    value = bytes[zero + cursor++];
-    value |= ((uint16_t) bytes[zero + cursor++]) << 8;
+    value = *ptr++;
+    value |= ((uint16_t) *ptr++) << 8;
     return value;
 }
 
 void ByteBuffer::copy(uint8_t *bytes, size_t length) {
-    canAccessIndex(cursor + length);
+    assertCanAccessRelative(length);
 
-    memcpy(bytes, &this->bytes[zero + cursor], length);
-    cursor += length;
+    memcpy(bytes, ptr, length);
+    ptr += length;
 }
 
-ByteBuffer ByteBuffer::view(size_t length) {
-    canAccessIndex(cursor + length);
-    size_t s = zero + cursor + length;
-    return ByteBuffer(bytes, s, s, cursor);
+ByteBuffer ByteBuffer::view() const {
+    DF << "cursor=" << getCursor() << ", size=" << getSize();
+    return view(end - ptr);
 }
 
-void ByteBuffer::checkAndUpdateSize(size_t newBytes) {
-    size_t newSize = zero + cursor + newBytes;
-    if (newSize >= capacity) {
-        throw ByteBufferException(string("Out of bounds! zero=") + to_string(zero) + ", cursor=" + to_string(cursor) + ", size=" + to_string(size) + ", capacity=" + to_string(capacity) + ", newSize=" + to_string(newSize));
+ByteBuffer ByteBuffer::view(size_t length) const {
+    assertCanAccessRelative(length);
+    return ByteBuffer(bytes, length, ptr, ptr + length);
+}
+
+void ByteBuffer::checkAndUpdateEnd(size_t newBytes) {
+    uint8_t *newPtr = ptr + newBytes;
+    if (newPtr >= end) {
+        throw ByteBufferException(string("New size is too large! cursor=") + to_string(getCursor()) + ", size=" + to_string(getSize()) + ", capacity=" + to_string(capacity));
+    }
+
+    if (newPtr > end) {
+        end = newPtr;
     }
+}
 
-    size = max(newSize, size);
+void ByteBuffer::assertCanAccessRelative(size_t diff) const {
+    assertCanAccessIndex(ptr + diff - 1);
 }
 
-void ByteBuffer::canAccessIndex(size_t index) {
-    if (zero + index >= size) {
-        throw ByteBufferException(string("Out of bounds! zero=") + to_string(zero) + ", index=" + to_string(index) + ", size=" + to_string(size));
+void ByteBuffer::assertCanAccessIndex(uint8_t *p) const {
+    if (p >= end || p < zero) {
+        throw ByteBufferException(string("Out of bounds! size=") + to_string(getSize()));
     }
 }
 
 std::string ByteBuffer::toString() const {
     stringstream s;
 
-    for(size_t i = zero; i < size; i++) {
-        s << hex << setfill('0') << setw(2) << (int) bytes[i] << " ";
+    for (uint8_t *i = (uint8_t *) zero; i < end; i++) {
+        s << hex << setfill('0') << setw(2) << (int) *i << " ";
     }
 
     return string(s.str());